qa/workunits/smb: add utility module for cephadm shell commands

Add a helper module that makes it a bit cleaner and easier to
find and interact with the cluster's 'admin node' the node where
we can run `cephadm shell` and commands within that shell.
This will allow us to make modifications to smb resources via
the ceph command and JSON in order to test various features.

Signed-off-by: John Mulligan <jmulligan@redhat.com>

diff --git a/qa/workunits/smb/tests/cephutil.py b/qa/workunits/smb/tests/cephutil.py
new file mode 100644 (file)
index 0000000..350b9db
--- /dev/null
+++ b/qa/workunits/smb/tests/cephutil.py
@@ -0,0 +1,68 @@
+import enum
+import json
+import subprocess
+
+
+class LoadJSON(enum.Enum):
+    NONE = 0
+    OUTPUT = 1
+    ERROR = 2
+    BOTH = 3
+
+    @classmethod
+    def convert(cls, value):
+        if isinstance(value, LoadJSON):
+            return value
+        if value:
+            return cls.OUTPUT
+        return cls.NONE
+
+
+class JSONResult:
+    def __init__(self, returncode, output, error):
+        self.returncode = returncode
+        self.raw_out = output
+        self.out = None if output is None else json.loads(output)
+        self.raw_err = error
+
+    @property
+    def obj(self):
+        return self.out
+
+
+def cephadm_shell_cmd(
+    smb_cfg, args, load_json=None, input_json=None, **kwargs
+):
+    """Run a command within the cephadm shell on the cluster's admin
+    node (derived via smb_cfg). If `load_json` is true return the stdout
+    loaded into a json object (implies check and capture_output).
+    All kwargs are treated as arguments to subprocess.run.
+    """
+    load = LoadJSON.convert(load_json)
+    if load is not LoadJSON.NONE:
+        kwargs['capture_output'] = True
+        kwargs['check'] = load is LoadJSON.OUTPUT
+    if input_json is not None:
+        kwargs['input'] = json.dumps(input_json).encode()
+    cmd = [
+        'ssh',
+        '-oBatchMode=yes',
+        '-oUserKnownHostsFile=/dev/null',
+        '-oStrictHostKeyChecking=no',
+        '-q',
+        f'{smb_cfg.ssh_user}@{smb_cfg.ssh_admin_host}',
+        'sudo',
+        f'/home/{smb_cfg.ssh_user}/cephtest/cephadm',
+        'shell',
+    ]
+    cmd += list(args)
+    proc = subprocess.run(cmd, **kwargs)
+    if load is LoadJSON.BOTH:
+        return JSONResult(
+            proc.returncode, proc.stdout.decode(), proc.stderr.decode()
+        )
+    elif load is LoadJSON.OUTPUT:
+        return JSONResult(proc.returncode, proc.stdout.decode(), None)
+    elif load is LoadJSON.ERROR:
+        return JSONResult(proc.returncode, None, proc.stderr.decode())
+    return proc